1. Field of the Invention
The present invention relates to a method of permanently marking indicia upon a compact disc, and to apparatus for accomplishing the method.
2. Description of the Piror Art
Compact discs have recently come into widespread use as a medium for recording video and audio data for subsequent reproduction. As these discs are small, light, and highly practical, it has also become widespread to lend and transport them. Accordingly, the opportunities for loss by theft, forgetfulness, and the like have increased.
Providing identifying markings on compact discs has been proposed in the prior art. U.S. Pat. No. 5,320,219, issued to David Ward on Jun. 14, 1994, discloses a kit for stamping indicia upon individual compact discs. The inscription is dependent upon the preformed stamp. No change to the selected indicia is possible without a new stamp. Also, this invention deposits ink on the surface of the compact disc which penetrates the disc, but does not distort the same. It would be possible for a person so motivated to alter the indicia by repeating the ink deposition step.
U.S. Pat. No. 5,090,561, issued to Donald Spector on Feb. 25, 1992, discloses a compact disc having indicia printed upon the unrecorded face.
A method of marking a synthetic polymeric substrate is illustrated in U.S. Pat. No. 4,578,329, issued to Albert Holsappel on Mar. 25, 1986. A laser beam is projected onto the substrate, and reacts with a radiation absorbing substance. Local decomposition of the substrate ensues, turning the substrate black. This patent describes a process which can be employed to form indicia upon the surface of a particular material similar to that of compact discs, but does not shed light on methods of controlling and selecting the indicia.
A machine having a programmable controller suitable for custom printing is disclosed in U.S. Pat. No. 5,056,029, issued to Thomas G. Cannon on Oct. 8, 1991. This patent describes certain facets of technology which could be adapted for use in the present invention. However, the present invention does not concern a printing process, and requires an additional degree of control compared to printing processes.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.